Accurately measuring the axial and radial, sometimes referred to as lateral, runout of a groove formed in the periphery of a pulley is of importance in significantly increasing the wear-life of either or both, the belt and pulleys utilized in a belt-pulley assembly.
Heretofore, various apparatus have been provided for this purpose; however, because of certain inherent design characteristics they have been beset with one or more of the following shortcomings: (a) the apparatus was incapable of simultaneously measuring axial and radial runout; (b) it was incapable of accommodating pulleys or the like which varied in size and shape over a wide range; (c) it was highly susceptible to malfunction; (d) it required an inordinate amount of service and maintenance; (e) it required a substantial amount of disassembly and assembly in order to substitute components for measuring various size pulley grooves; (f) it was incapable of accurately measuring the runout of the side surfaces forming the groove.